Thread clamping,releasing,and feeding mechanism for spinning apparatus

ABSTRACT

Rollers for drawing spun thread from spinning apparatus are located closely adjacent to the apparatus outlet. The mouth of an outlet tube may be shaped to terminate close to the nip of the withdrawing rollers and may be flared longitudinally of the roller axes. The withdrawing rollers are normally biased together and are movable out of engagement by a solenoid plunger reciprocated in response to a thread-sensing device to release the thread and provide access to the spinning apparatus outlet. A drive roller, which may be one of the withdrawing rollers, may simultaneously serve several spinning outlets. Individually operable sensors and plungers may disengage from the drive roller individual, drive-roller-engaging withdrawing rollers. One of the withdrawing rollers may be cantilever mounted and its free end beveled to feed automatically thread dropped into the slot formed by the bevel to a position between the pair of withdrawing rollers forming a straight thread stretch between the outlet and thread winding rollers.

United States Patent Landwehrkamp et al.

[ 1 Aug. 22, 1972 THREAD CLAMPING, RELEASING,

AND FEEDING MECHANISM FOR SPINNING APPARATUS [72] Inventors: HansLandwehrkamp; Franz Schreyer, both of Ingolstadt; Karl Handschuch,Oberhaunstadt, all of Germany [73] Assignee: Schubert & SalzerMaschinenfabrik Aktiengesellschaft, Ingolstadt, Germany [22] Filed:April 3, 1968 [21] Appl.No.: 718,436

[30] Foreign Application Priority Data April 18, 1967 Germany ..Sch40567 [52] US. Cl ..57/34 R, 57/58.95, 57/80, 5 7/84 [51] Int.Cl......D01h l/12, D01h 13/16, D01h 15/00 [58] Field of Search ..57/34,58.89-58.95, 57/84, 80, 78, 90

[56] References Cited UNITED STATES PATENTS 2,407,730 9/ 1946 Wethers..57/90 7 2,952,115 9/1960 Bromley ..57/90 X 3,163,976 l/l965 Juillard..57/58.89 3,279,667 10/1966 Scragg et al. ..57/90 X 3,354,626 11/1967Cizek et a1 ..57/78 2,019,673 11/1935 Gow ..57/84 2,482,654 9/ 1949Cochran et al. ..57/84 X 2,599,256 6/1952 Hartley et a1 ..57/843,354,631 11/1967 Elias et al. ..57/58.95

FOREIGN PATENTS OR APPLICATIONS 1,467,507 12/1966 France ..57/58.95

Primary Examiner.lohn Petrakes Attorney-Robert W. Beach 57 ABSTRACTRollers for drawing spun thread from spinning ap-' paratus are locatedclosely adjacent to the apparatus outlet. The mouth of an outlet tubemay be shaped to terminate close-to the nip of the withdrawing rollersand may be flared longitudinally of the roller axes. The withdrawingrollers are normally biased together and are movable out of engagementby a solenoid plunger reciprocated in response to a thread-sensingdevice to release the thread and provide access to the spinningapparatus outlet. A drive roller, which may be one of the withdrawingrollers, may simultaneously serve several spinning outlets. Individuallyoperable sensors and plungers may disengage from the drive rollerindividual, drive-roller-engaging withdrawing rollers. One of thewithdrawing rollers may be cantilever mounted and its free end beveledto feed automatically thread dropped into the slot formed by the bevelto a position between the pair of withdrawing rollers forming a straightthread stretch between the outlet and thread winding rollers.

7 Claims, 7 Drawing Ilgures P'A'IENTED M22 1912 3 685. 26

SHEET 1 UF 3 I Fig. Iv

in I] BY I 60% 1 THREAD CLAMPING, RELEASING, AND FEEDING MECHANISM FORSPINNING APPARATUS In continuous-spinning devices the fiber sliver issupplied to a spinning chamber which has an area for collecting fiberfrom the sliver and binding and twisting it to produce thread. Thread iswithdrawn from the spinning apparatus by withdrawing mechanism, usuallyin the form of pulling rollers, exteriorly of the spinning apparatus.The withdrawing process is continuous so that the spinning apparatusmust have an opening in it through which the strand can be withdrawnwhether the spinning is accomplished by a cup-shaped rotary chamber suchas Shown in copending application Ser.

No. 655,906 of Landwehrkamp and Schreyer, filed July 25, 1967, or by arotating funnel to which fiber is fed electrostatically as disclosed inFrench Pat. No. 1,442,699, or by a chamber into which the fiberparticles are carried by fiuid and collected by the free-rotating end ofa thread, such as disclosed in German Pat. No. 1,062,153.

In all devices of the continuous-spinning type, when the spinningprocess is stopped or the thread breaks in the spinning apparatus thewithdrawing rollers have continued to pull the thread from the machineor, if the rollers are stopped, the tension in the thread caused by thetwist being formed in it will cause the thread to spring out of thespinning apparatus when the tension,

. spinning apparatus, the withdrawing mechanism has heretofore beenspaced from the spinning apparatus outlet mouth. Consequently, there hasbeen in conventional spinning apparatus a relatively long unguidedthread stretch'between the spinning apparatus outlet and the withdrawingmechanism so that a discontinuity of the thread due to a thread break ormachine shut down has frequently resulted in the trailing thread endbeing pulled from the spinning apparatus to dangle uncontrolled from thewithdrawing mechanism. In order to start the spinning process again thefree end of the thread must be fed back into the apparatus through theopening provided for its withdrawal until its end is again in a positionto collect fiber fed to themachine. Effective apparatus for clamping thethread and feeding the thread end back into the spinning apparatus isdisclosed in copending application Ser. No. 665,1 18, of

Landwehrkamp et al., filed Sept. 1, 1967. This apparatus, however,requires additional mechanism which makes the spinning machine morecomplicated mechanically and, therefore, increases theexpense inmanufacture and maintenance.

It is therefore a principal of the present invention to provide clampingmeans for preventing removal of the free thread end from an outletpassage in a continuous spinning machine, either when the spinningmachine is stopped or when the thread breaks, 'by modifying conventionalspinning components and thereby to simplify the machine mechanism.

It is a further important object to provide such clamping means whichsubstantially reduces the number and complexity of components which hasbeen necessary for previously proposed clamping devices.

It is an incidental object to provide a spinning machine which is morecompact than previously known machines.

paratus, which figure includes a diagrammatic representation of circuitcontrolmeans.

FIG. 4in an end elevation of a different form of clamping mechanism withparts in section.

FIG. 5 is a side elevation. of thread-withdrawing mechanism includingclamping apparatus for a plurality of spinning chambers, with partsbroken away.

F IG. 6 is an end elevation of still a different form of clampingapparatus.

FIG. 7 is an c'levational detail of a drawing roll which can be usedwith any of the structures shown in FIGS. 1 through 6.

The restraining apparatus of the present invention is shown inconnection with a rotary spinning chamber 2 enclosed in a housing 1 andhaving a'cover 11. Fiber sliver S is fed to the spinning chambercollection channel 24 through feed rollers 5 and feed tube 51 extendingthrough the cover 11. The spun thread is withdrawn through a withdrawalpassage provided within an upright withdrawal tube 6. The thread F ispulled from the spinning chamber 2 through tube 6 by a pair ofwithdrawing rollers 3,3 and is wound into a spool 9 by winding roller 8.Withdrawing rollers 3,3 are located closely adjacent to and directlyabove outlet 61 of the withdrawal tube. When the spinning machine isstopped for any reason, the withdrawing rollers 3,3 also stop, butthread F is clamped between the stopped rollers and because there is nospace between the withdrawing rollers and tube outlet 61, the rollerswill not have pulled such thread out of the tube. Also because suchrollers are so close to the tube end the thread will not spring up outof the tube when the spinning tension is released.

In order to prevent removal of the trailing end of the thread fromwithdrawal tube 6 when the thread breaks, a sensor is inserted in theside of such tube a considerable distance below its outlet 61. Thesensor could be a photoelectric device responsive to the absence of athread stretch between a light source on one side of the tube and aphotoelectric cell diametrically opposite the light source.Alternatively, as shown in FIG. 1, a sensor 7 could be providedresponsive to a decrease in tension in the thread, which would occur ifthe thread should break or if the speed of the spinning chamber rotationshould be reduced. If the thread tension is decreased,

sensor 7 would complete a circuit with switch contact 7.1 to actuatecontrol 72 and thereby effect deenergization of the spinning apparatusand particularly of the drive for withdrawing-rollers 3,3. Control 72might also actuate return mechanism for returning the broken thread endto the spinning chamber collection channel 24 and reenergize thespinning chamber and withdrawing roller drive, for example. The Sequenceof operations effected by control 72 would dependon the type of spinningapparatus used, whether it is a rotary spinning chamber, or anelectrostatic or pneumatic spinning device, for example. The primaryfunction of control 72 for the purpose of the present invention,however, is immediately to deenergize or disengage the drive for rollers3,3 to prevent the trailing thread end from being drawn out of tube 6.

After the withdrawing rollers have been stopped, it is necessary tomovethe free thread end down tube 6 until the thread end is located inthe spinning chamber 2 adjacent to collection channel 24 so that fibercan again be spun continuously from the thread end. This can beaccomplished by reversing the direction of rotation of rollers 3,3,spool 9 and winding roller 8 for a short time, and then reversing suchrollers and spool to rotate in their normal spinning direction when thespinning chamber has attained its normal spinning rotational speed.

To facilitate the thread return, if the thread end is close to the nipof rollers 3,3 when they are stopped, the outlet end 61 of tube 6 can beshaped as shown in FIGS. 1 and 2. The mouth of the outlet tube isflattened so that, in cross-sectional profile perpendicular to the lineof contact I(' of rollers 3,3, such mouth is tapered inwardly or flaredoutwardly with the tapered tubewalls having concave curvaturecomplemental to the curvature of the adjacent roller circumference. FIG.2 is a cross section through tube outlet 61 parallel to roller contactline K of FIG. 1 showing that the outlet is flared outwardly in an axialplane of the tube 6 which plane is parallel to the axes of thetwo-withdrawing rollers 3 and 3. Preferably, the widest portion of theflared outlet has an extent parallel to roller contact line K at leasttwice as great as the distance between such contact line and the rim ofthe outlet so that, when the end of the thread is located above theoutlet rim, the thread end portion below the nip of the rollers willalways be of shorter lengththan the width of the outlet opening. Withsuch construction there is virtually no chance that the thread wouldcatch on the outlet rim and slip outside of the withdrawal tube. Thisconstruction is particularly important when a thread break occurs tooclose to the rollers to prevent the thread end from passing between therollers, or when a different type of thread is to be spun so that thepreviously spun thread has been pulled completely out of the machine andnewstarting thread is to be supplied to the spinning chamber through thewithdrawal tube.

As indicated in FIG. 5, a single spinning machine usually includesseveral spinning stations, each having a spinning chamber from whichthread is' withdrawn through a tube 6. In such a multistation spinningmachine, one of the withdrawing rollers may be a single continuous driveroller 3 which will frictionally drive individual rollers 3' for eachstation. Each pressure roller 3' has one end mounted in a beatingcarried by one end of a swingable arm 391. The other arm end ispivotally supported on a rod 39. A torsion spring 38 connected betweenrod 39 and arm 391 biases such arm to press its roller 3 into engagementwith drive roller 3. Similarly, winding roller 8 is a continuous rollercooperating with individual thread spools 9.

FIG. 3 illustrates a withdrawing roller mounting and thread returnmechanism which are simple in construction and operation and whicheliminate the necessity for reversing mechanism for the drawing rollersand for winding roller 8 and spool 9. As in FIG. 1, the nip ofwithdrawing rollers 31, 31' is perpendicular to the axis of withdrawaltube 6 and the rollers are located directly above and close to the tubeoutlet. Roller 31 is preferably positively driven. Roller 31 is drivenby frictional' engagement with roller 31 and is mounted in floatingbearings so that such roller can be moved into and out of engagementwith roller 31 by reciprocation of the plunger of solenoid 32.

' Thread take-up mechanism is provided in the form of a swingable arm 35which is normally held in the raised full-line position by anelectromagnet 36 attracting an armatureswingable with the arm so thatthread F is guided between the rollers 31,31 and winding roller 8 in anangular path displaced laterally from a straight line joining suchdrawing rollers and winding roller 8. When sensor 7' engages switchcontact 71 to actuate control 72, such control first effectsdeenergization of rollers 31,31 and then, after a preset time interval,deenergizes solenoid 32 so that its plunger and roller 31' are moved tothe right to release the thread previously clamped between the twowithdrawing rollers. Simultaneously or subsequently, electromagnet 36 is'deenergized by control 72 to release the armature of arm 35- so thatsuch arm will swing down into the broken line position and the threadwill assume the straight line position indicated in broken lines in FIG.3 to provide sufficient reserve thread to return the thread end to thecollection channel of the spinning chamber.

When spinning is resumed, solenoid 32 isagain energized to press roller31 into engagement with roller 31. Mechanism for gradually swinging arm35 upward againinto its raised position may be provided, or thewithdrawing rollers may be started slightly ahead of the winding roller8 and spool 9 to provide slack to be taken up by swinging arm 35 backinto the solid line position.

As in FIG. 5, roller 31 may be a continuous drive roller fora pluralityof spinning stations and individual pressure rollers 31', solenoids 32,take-up arms 35 and sensors 7 can be provided for each station so as tobe responsive to individual thread breaks and thereby avoid interruptingseveral spinning stations in response to a break at one station.

It has been found that the withdrawing rollers can be spaced from thewithdrawaltube while satisfactorily preventing removal of the threadfrom the tube without the necessity of providing take-up mechanismbetween the tube outlet and the withdrawing rollers if the distancebetween the tube outlet tip and the withdrawing roller contact line K isno more than one-third of the'length of withdrawal tube 6. If thewithdrawing rollers are offset slightly from the axis of tube 6, thespinning operation can be more readily observed by an operator. Inaddition, accessibility to the outlet of the withdrawal tube, such asfor machine service, is facilitated if at least one of the rollers ismounted in floating bearings so that it can be moved away from thewithdrawal tube, such as shown in FIG. 3.

In FIG. 4 mechanism is shown whereby both withdrawing rollers 311 and311 can be moved away from the withdrawal tube 6. Withdrawing roller 311is mounted on one end of a swinging arm 393, the opposite end of sucharm being pivotably mounted by a pin 39' to the machine frame. Roller311 is mounted on a swinging arm 392, the opposite end of which arm isalso mounted on pivot pin 39'. A tension spring 37 connected betweenswinging arms 392 and 393 normally biases the rollers into engagement.Withdrawing roller3ll is biased into engagement with a separate fixeddrive roller 310, which may drive the withdrawing rollers of severalspinning stations, by a tension spring 34 connected between arm 393 andthe machine frame. Instead of a pin 39,.a common rod may mount severalswinging arm pairs, similar to rod 39 in FIG. 5.

The withdrawing rollers are stopped without stopping roller 310 bydisengaging roller 311 from drive roller 310. Such disengagement iseffected by a lifting element 33, which may be a solenoid plunger or afluid-actuated plunger for example. The plunger presses against arm 392,mounting roller 311', to pivot such arm about pivot pin 39'. If arm 392is swung in a clockwise direction as seen in FIG. 4, spring 37 will pullarm 393 along with arm 392 so that roller 311 is lifted off drive roller310. As the plunger is further extended to the upper left of FIG. 4, aprojection 394 on arm 393 will engage a stop 395 so that continuedextension of the plunger will swing arm 392 away from arm 393 todisengage roller 31 1 from roller 311 and thereby release thread clampedby the withdrawing rollers for returning a thread end to the spinningchamber.

In some spinning machines it may not be desirable for the withdrawingroller axes to extend parallel to the axis of a continuous drive roller.For example, it may be desirable to have two or more rows of spinningstations on opposite sides of a single drive mechanism for all-of thewithdrawing rollers. F IG. 6 discloses drawing mechanism which would besuitable for spinning stations which are offset from the single drivemechanism. The shaft of one of the pair of rollers 312 is mounted in afixed bearing and such shaft carries a gear 313 driven by a worm 314rotated by shaft 310. Consequently, the contact line K of thewithdrawing rollers is perpendicular to the axis of drive roller 310.Such an arrangement of the withdrawing rollers also provides betteraccessibility to the withdrawal tube 6 and its spinning chamber becausethe withdrawing rollers and their drive mechanism are offset to one sideof the station so that the remaining three sides are unobstructed.

When a spinning machine is to be started with a different color ortexture of fiber, for example, a starting thread must be suppliedthrough withdrawal tube 6 to the spinning chamber. If each spinningstation is provided with at least one withdrawing roller 3 mounted on acantilever shaft, such as shown in FIG. 5, the starting thread cansimply be pulled across the end of the roller into engagement with thedrive roller 3 and then pulled axially along the drive roller until thethread is engaged between the two rollers. The thread must usually bepulled in the axial direction until the thread stretch between spool 9and withdrawal tube 6 assumes a straight line. This starting procedureis facilitated if the straight line position of thread F, as shown inFIG. 5, intersectsthe contact line K of the withdrawing rollers near thefree end of a cantilever roller 3' to shorten the axial distance alongwhich the machine operator each withdrawing roller may have a beveledcircumferential end to provide a deeper slot.

Alternatively, the thread stretch F spanning from the I winding roller 8to the outlet of withdrawal tube 6 may be located in the desiredspinning position between the rollers .of the withdrawing roller pair byproviding means for reciprocating a cantilever withdrawing rollerlengthwise of its axis. In the construction in FIG. 5, for

example, arms 391 mounting rollers 3' may be slidable along rod 39 tothe left from the positions shown so that the free ends of the rollerswould be at-the left of the thread line F.- In supplying a-startingthread to the withdrawal tube, therefore, the operator can simply dropthe thread into the tube. Such thread would auto matically assume theposition indicated by the broken line F. Cantilever pressure roller 3would then be shifted axially along rod 39 to the right into theposition shown in'FIG. 3. If desired the rollers 3' at all of thestations could be shifted simultaneously by moving rod 39 lengthwise. Inthe constructions of FIGS. 4 and 6 in which both drawings rollers arecantilever mounted, either one or both of the withdrawing rollers may beaxiallyshiftable to locate the thread between the rollers. Preferablythe withdrawing rollers are in their spaced thread-releasing positionsduring such lengthwise shifting. (Further reciprocating lengthwiseshifting of the drawing rollers while the thread withdrawal operationmay be provided for elimination of extreme wear of a singlecircumferential line of the withdrawing rollers).

The withdrawing mechanism shown in FIG. 6 further facilitates thestarting operation because in this construction the operator need onlydrop the thread end into tube 6 and lay a stretch of the thread in theflaring groove between the free ends of rollers 312. The axes of thewithdrawing rollers are arranged so that the contact line K between themis perpendicular to the common tangent to winding roller 8, spool 9, athread guide element which may be a roller 81 spaced from roller 8and'the withdrawing rollers. Such tangent preferably intersects the axisof withdrawal tube 6 at the outlet inclined from their free ends. Thewithdrawing roller arrangement of the present invention provides asimple construction for clamping thread and thereby maintaining thethread in the withdrawal tube of an open-end spinning machine and canalso effect return of the thread toward the spinning chamber in someinstances without additional clamping devices. In addition, thearrangement of the present invention is considerably more compact thanwithdrawing and thread-clamping mechanism which has been providedpreviously. The mechanism disclosed herein can be readily andeffectively used with all open-end spinning machines.

We claim:

1. Thread control mechanism for spinning machines including a threadwithdrawal passage for withdrawing thread out of a continuous ringlessspinning mechanism and a pair of withdrawing rollers contacting along aline for withdrawing thread through such thread withdrawal passage,wherein the improvement comprises means mounting at least one of thewithdrawing rollers in cantilever fashion by one axial end to leave theopposite axial end of such roller free, and the rollers being disposedso that the thread withdrawal passage axis intersects the contact lineof the withdrawing rollers for movement of a stretch of thread,extending from the thread withdrawal passage, in a directiontransversely of its length past said free axial end of saidcantilevermounted roller into position between the withdrawing rollers.

2. The thread control mechanism defined in claim 1, in which themounting means mounts a cantilevermounted roller with its axis inclinedat an acute angle to the axis of the thread withdrawal passage and theaxis of the thread withdrawal passage intersects the contact lines ofthe withdrawing rollers at a location ad.- jacent to the free axial endof such cantilever-mounted roller.

3. Thread control mechanism for spinning machines having a plurality ofspinning stations, each station including a thread withdrawal passagefor withdrawing thread out of a continuous ringless spinning mechanismand a pair of withdrawing rollers located closely adjacent to suchthread withdrawal passage for withdrawing thread therethrough, a driveshaft common to said plurality of spinning stations and driving onewithdrawing roller of each pair, the other withdrawing roller of eachpair being a pressure roller engageable with the withdrawing rollerdriven by said drive shaft, and separate disengaging means for eachstation operable individually initially to withdraw conjointly both ofsaid withdrawing rollers of the pair of withdrawing rollers at aselected spinning station from said drive shaft independently of thewithdrawing rollers at the other spinning stations and thereafter todisengage from each other said withdrawing rollers of the withdrawingroller pair at such selected spinning station.

4. Thread control mechanism for spinning machines comprising a pluralityof spinning stations, each station including a thread winding meanshaving a thread spool and a winding. roller engageablev with such spool,a

thread withdrawal passage for withdrawing thread out a of a continuousringless spinning mechanism, a pair of withdrawing rollers contactingalong a line and located closely adjacent to said thread withdrawalpassage for withdrawing thread therethrough, a thread guide elementlocated between said withdrawing rollers and said thread winding meansso that a line connecting said thread withdrawal passage and said threadguide element intersects the roll-contacting line, one of said alill hall ilfill fiiig sfifg eisillil iir 'ii iilfi 3%; fashion by one axialend to leave the opposite axial end thereof free for movement of astretch of thread in a direction transversely of its length past saidfree axial end of said cantilever-mounted roller into position betweensaid withdrawing .rollers, and a drive shaft common to said pairs ofwithdrawing rollers of said plurality of spinning stations, the axes ofsaid withdrawing rollers being perpendicular to the axis of said commondrive shaft.

5. The thread control mechanism defined in claim 4, in which .the freeaxial end of each cantilever-mounted pressure roller has a beveledcircumference to facilitate entrance of a thread between suchcantilever-mounted pressure roller and the other roller of the pair ofwithdrawing rollers.

6.- Thread control mechanism for spinning machines comprising a threadwithdrawalpassage for withdrawing thread out of a continuous ringlessspinning mechanism, and a pair of withdrawing rollers located closelyadjacent to the thread withdrawal passage mouth, the mouth of saidthread withdrawal passage adjacent to said withdrawing rollers beingflared outwardly only in that axial plane of said thread withdrawalpassage which is parallel to the axes of said withdrawing rollers andsaid thread withdrawal passage mouth is not flared in the axial plane ofsaid thread withdrawal passage perpendicular to the axes of saidwithdrawing rollers.

7. Thread control mechanism for spinning machines comprising a threadwithdrawal tube having a passage for withdrawing thread out of acontinuous ringless spinning mechanism, and a pair of withdrawingrollers located closely adjacent to said thread withdrawal passage, saidthread-withdrawal tube having an end adjacent to said withdrawingrollers located between and conforming to the rounding of the rollers ofsaid pair of withdrawing rollers, said passage being of substantiallyuniform width throughout its entire length in the axial plane ofsaidftube perpendicular to the axes of said withdrawing rollers tolocate the end of said passage close to the nip of said rollers.

1. Thread-control mechanism for spinning machines including athread-withdrawal passage for withdrawing thread out of a continuousringless spinning mechanism and a pair of withdrawing rollers contactingalong a line for withdrawing thread through such thread-withdrawalpassage, wherein the improvement comprises means mounting at least oneof the withdrawing rollers in cantilever fashion by one axial end toleave the opposite axial end of such roller free, and the rollers beingdisposed so that the thread-withdrawal passage axis intersects thecontact line of the withdrawing rollers for movement of a stretch ofthread, extending from the thread-withdrawal passage, in a directiontransversely of its length past said free axial end of saidcantilever-mounted roller into position between the withdrawing rollers.2. The thread-control mechanism defined in claim 1, in which themounting means mounts a cantilever-moUnted roller with its axis inclinedat an acute angle to the axis of the thread-withdrawal passage and theaxis of the thread-withdrawal passage intersects the contact lines ofthe withdrawing rollers at a location adjacent to the free axial end ofsuch cantilever-mounted roller.
 3. Thread-control mechanism for spinningmachines having a plurality of spinning stations, each station includinga thread-withdrawal passage for withdrawing thread out of a continuousringless spinning mechanism and a pair of withdrawing rollers locatedclosely adjacent to such thread-withdrawal passage for withdrawingthread therethrough, a drive shaft common to said plurality of spinningstations and driving one withdrawing roller of each pair, the otherwithdrawing roller of each pair being a pressure roller engageable withthe withdrawing roller driven by said drive shaft, thread-withdrawaldisengaging means for each station operable individually initially towithdraw conjointly both of said withdrawing rollers of the pair ofwithdrawing rollers at a selected spinning station from said drive shaftindependently of the withdrawing rollers at the other spinning stationsand thereafter to disengage from each other said withdrawing rollers ofthe withdrawing roller pair at such selected spinning station. 4.Thread-control mechanism for spinning machines comprising a plurality ofspinning stations, each station including a thread-winding means havinga thread spool and a winding roller engageable with such spool, athread-withdrawal passage for withdrawing thread out of a continuousringless spinning mechanism, a pair of withdrawing rollers contactingalong a line and located closely adjacent to said thread-withdrawalpassage for withdrawing thread therethrough, a thread-guide elementlocated between said withdrawing rollers and said thread-winding meansso that a line connecting said thread-withdrawal passage and saidthread-guide element intersects the roll-contacting line, one of saidwithdrawing rollers of each pair being a pressure roller, and meansmounting said pressure roller in cantilever fashion by one axial end toleave the opposite axial end thereof free for movement of a stretch ofthread in a direction transversely of its length past said free axialend of said cantilever-mounted roller into position between saidwithdrawing rollers, and a drive shaft common to said pairs ofwithdrawing rollers of said plurality of spinning stations, the axes ofsaid withdrawing rollers being perpendicular to the axis of said commondrive shaft.
 5. The thread-control mechanism defined in claim 4, inwhich the free axial end of each cantilever-mounted pressure roller hasa beveled circumference to facilitate entrance of a thread between suchcantilever-mounted pressure roller and the other roller of the pair ofwithdrawing rollers.
 6. Thread-control mechanism for spinning machinescomprising a thread-withdrawal passage for withdrawing thread out of acontinuous ringless spinning mechanism, and a pair of withdrawingrollers located closely adjacent to the thread-withdrawal passage mouth,the mouth of said thread-withdrawal passage adjacent to said withdrawingrollers being flared outwardly only in that axial plane of saidthread-withdrawal passage which is parallel to the axes of saidwithdrawing rollers and said thread-withdrawal passage mouth is notflared in the axial plane of said thread-withdrawal passageperpendicular to the axes of said withdrawing rollers.
 7. Thread-controlmechanism for spinning machines comprising a thread-withdrawal tubehaving a passage for withdrawing thread out of a continuous ringlessspinning mechanism, and a pair of withdrawing rollers located closelyadjacent to said thread-withdrawal passage, said thread-withdrawal tubehaving an end adjacent to said withdrawing rollers located between andconforming to the rounding of the rollers of said pair of withdrawingrollers, said passage being of substantially uniform width throughoutits entire length in the axial plane of said tube perpendicular to theaxes of said withdrawing rollers to locate the end of said passage closeto the nip of said rollers.